Re: Electronics Projects and PC Interfacing

[mattkotys@gmail.com]

Thanks very much for the insights.

Tim, I will order an Arduino kit when my wife isn't looking.  I already have a PICkit2 and several breadboards, misc ICs, ... so I can play with those throughout the holidays, but Make magazine and others have certainly sold me on that platform.  The Morse decoder seems like a formidable challenge - maybe just the right project for a GPL debut.  I've never published any software before, and eager to get my feet wet.  I'll let LUCI know about my progress.

Don and Herbie - I see from http://www.epanorama.net/circuits/parallel_output.html that a darlington uln2803 array will make it safer to do this stuff.  And maybe I will find a proper LCD to use, rather than a hack.

Let me know if you have any ideas for these and other cool projects.


Sent from my Verizon Wireless BlackBerry

-----Original Message-----
From: Don Parth <don-p@comcast.net>
Date: Sat, 19 Dec 2009 12:30:29 
To: <luci-discuss@luci.org>
Subject: Re: Electronics Projects and PC Interfacing

I haven't messed with direct hardware interfacing in a long, long time. 
  Generally, USB and serial ports are best used for communications, with 
a computer (i.e. PIC) on the other end to decode.

If you want to directly control the wires, say to control a stepper 
motor, I think the parallel port would be the one to use.  It has at 
least 12 output and 5-13 input lines (all modern ports can be made 
bi-directional).  But here is a 2006 link to get a TV remote to talk to 
a serial port:
http://www.linuxjournal.com/article/8811
and here is a 2004 article on writing your own USB driver to control a 
specific USB device:
http://www.linuxjournal.com/article/7353

Most information on direct hardware port interfaces will be from the 
last millennium.  Here is a link to a 1998 article on parallel port 
interfacing with examples in C:
http://www.linuxjournal.com/article/2662

For the nasty low-level details on how to build electronic interfaces at 
the wire level, look to electronic magazines - Circuit Cellar 
(especially stuff from the 80's), and defunct magazines like Popular 
Electronics, Radio-Electronics, and Byte. These had a lot of info in the 
late 70's and early 80's.  Libraries probably have dead-tree archives of 
these.  Also look to the amateur radio magazines, maybe Nuts & Volts, 
and possibly Make. Also look for books on building robots.

Good luck on your projects!
Don

On 12/18/2009 04:49 PM, Herbie wrote:
> Way, way back in the day I was using a Darlington Transistor Array to
> buffer/amplify the signals on a parallel I/O on the old BBC Micro they
> used in schools in the UK, part of a class project I was assisting in.
>
> My other thought is to look at the Linux Car MP3 player. CAJUN.
>
> http://cajun.sourceforge.net/
>
> as it has LCD drivers as part of it's code, but it's using a serial
> driveable LCD not just some random calculator display, but it may help.
>
> h.
>
> On Fri, 18 Dec 2009, Matthew Kotys wrote:
>
>> Does anybody here have experience with electronics design, and
>> interfacing
>> USB / Serial / Parallel ports on Linux hosts? My intent is to mess around
>> with controlling DC/stepper motors, temperature sensors, maybe a USB
>> <--> IR
>> adapter for TV remotes. I have done a few "Hello World" projects on PIC
>> uCs, but I'm sort of bored with blinking lights in succession and
>> triggering
>> a piezo buzzer. I have a basic understanding of DC circuits, but I'm
>> not so
>> good at peripherals and drivers. I use C, Perl, Python, PHP, bash
>> scripting
>> all the time...
>>
>> Maybe I would start like this:
>>
>> project 1: build a USB morse code receiver, translating to text as it
>> takes
>> in user input
>> The translation software for this would be interesting to write
>>
>> project 2: build a USB morse code* transceiver*, allowing for tty
>> sessions
>> entirely in morse - (funny)
>>
>> project 3: rip out an LCD from an old calculator, connect it to a
>> keyboard
>> and a breadboard, and run a serial (or USB) cable across the room from my
>> PC. So, an actual (and really dumb) tty
>>
>> Any pushes in the right direction are welcome, since googling tends to
>> make
>> the hours pass way too quickly.
>>
>> --
>> Matt Kotys
>>
>
> -
> To unsubscribe, send email to majordomo@luci.org with
> "unsubscribe luci-discuss" in the body.
>

-
To unsubscribe, send email to majordomo@luci.org with
"unsubscribe luci-discuss" in the body.


-
To unsubscribe, send email to majordomo@luci.org with
"unsubscribe luci-discuss" in the body.